(東北大學 EPM重點實驗室, 沈陽 110004)
摘 要: 采用力學性能和電導率測試及透射電鏡組織觀察的方法, 研究了7050合金擠壓帶板的單級時效、 雙級時效及兩級時效之間處理條件對合金組織和性能的影響。 結果表明： 7050合金在120 ℃時效有很高的抗過時效能力, 抗拉強度超過619 MPa, 但電導率較低僅為32.3％IACS； 采用第二級時效溫度為165 ℃的雙級時效, 合金可獲得強度為551 MPa和電導率為40.6％IACS的配合；雙級時效過程的兩級時效之間處理條件對合金的強度有明顯的影響, 間斷時效和第一級時效后快冷有利于提高合金的強度；經過第一級時效后空冷再進行165 ℃、 16 h時效, 合金的強度和電導率分別為559 MPa和40.2％IACS。
關鍵字: 7050鋁合金； 雙級時效； 擠壓帶板； 電導率； 析出相
properties of 7050 aluminium alloy
（The Key Laboratory of Electromagnetic Processing of Materials,
Mnistry of Education, Northeastern University, Shenyang 110006, China）
Abstract: The effects of single aging, duplex aging and conditions between the first and second step agings on the microstructures and properties of the extruded plate of 7050 aluminium alloy were investigated, by means of TEM, tensile and conductivity tests. The results show that 7050 aluminium alloy aged at 120 ℃ can obtain tensile strength of 619 MPa and conductivity of 32.3％IACS, and its overaging at that temperature needs long time. 7050 aluminium alloy after duplex aging with the second-step aging at 165 ℃ can obtain the combinations of the tensile strength of 551 MPa and the conductivity of 40.6％IACS. Obvious effects of the treatment conditions exist between the first and second step agings on the tensile strength of 7050 aluminium alloy during duplex aging. The tensile strength of 7050 aluminium alloy can be increased as stop aging or quick cooling after the first step aging during duplex aging. 7050 alloy can obtain tensile strength of 559 MPa and conductivity of 40.2％IACS when it is aged at 165 ℃ for 16 h after air cooling following the first step aging.
Key words: 7050 aluminium alloys; duplex aging; extruded plate; conductivity; precipitates
